The invention relates to an apparatus for registering a scene, especially for its reproduction on the screen of a video monitor. The apparatus has a housing, a lens mounted on the housing for projecting an image of the scene on a focal plane, a video pickup disposed in the housing, situated in the said focal plane and being of a bidimensional configuration for converting the brightness and, if desired, the hue of individual points of a portion of the image into electrical signals, the video pickup being displaceably mounted and smaller than the image. The apparatus also has a driving mechanism for shifting the video pickup in the focal plane.
Apparatus of this kind, described in German Federal Patent Nos. 32 23 971 and 36 06 765, are usually referred to and used as TV cameras, and are known in a great number of embodiments. Their photosensitive pickup elements usually consist of a CCD line sensor, i.e., a charge-coupled semiconductor component ("charge-coupled device"), which has a plurality of tiny CCD cells arranged in a row, whose charge can be controlled analogously by light, and has a length of several millimeters. The linear video pickup is associated with one line of the imaged scene and can be driven by a driving mechanism perpendicularly to the lines, in order to scan the entire scene. One advantage of such CCD components is that the picture information falling ing on them can be transferred in the form of electrical signals to a register and the image or video signal can be obtained by reading the register, without using a scanning electron beam. However, the need for the entire camera to remain stationary at least until the line sensor has once scanned the entire scene makes it unsuitable for a number of practical applications.
In addition to the line sensor, such TV cameras can also be equipped with additional CCD areal sensors as described in German Federal Offenlegungsschrift Nos. 36 06 765 and 36 16 400, which serve, for example, as finders for locating the scene to be recorded and in this case are rigidly mounted, or are present in addition to the actual video pickup to perform fine adjustments in addition to the actual video pickup and can for this purpose be moved about together with the latter.
Also, there are TV cameras in CCD technology whose video pickups consist of surface sensors and are mounted like the video pickups of conventional TV cameras (vidicons, iconoscopes, orthicons or the like) fixedly in the camera body. Such cameras are suitable also for recording motion.
The known apparatus have it in common that the lens, the video pickup and the apparatus connected therewith are disposed and mounted in the camera body such that always the entire scene coverable by the camera, corresponding to its "field of view," is scanned by the video pickup. If the scene to be recorded is larger than the field of view, or if the scene passes out of this field of view, the entire camera with all the parts contained in it must be subjected to a swinging and turning movement. The same is true when, for example, a moving object is to be followed with the camera. Both applications often entail considerable physical or constructructional effort, because considerable masses have to be moved and enough space must be available to perform the swinging and turning movements. To avoid such movements it would be possible by selecting suitable lenses (wide-angle lenses, so-called "fish-eye" lenses) to assure that even very large scenes can be covered entirely by the camera or that moving objects will always be in the camera's field of view. This, however, would detract from the quality of reproduction, because still only the video pickups present in the individual case can serve to resolve the enlarged field of view.
On account of these circumstances, apparatus of the kind referred to above can be used to only a limited extent, especially for surveillance purposes of all kinds, but also for live pickups with rapidly changing scene locations, as is often the case at sporting events or the like. In the case of TV cameras mounted in buildings, as for example in banks or hotels, for the surveillance of large lobbies or waiting rooms, the field of view is either limited or an object located in it is visible but very unclearly, so that complex measures must be taken to mount the camera so as to be able to swing or rotate. In the case of swinging and rotating TV cameras disposed out of doors, for example at intersections and on roads for surveillance of traffic, the apparatus needed for the turning and rotation of the cameras are subject also to great wear by weather, dust, or the like, unless complex sealing systems are provided. In the case of cameras that have to be moved entirely or partly by hand, the great masses that have to be moved often create problems for the cameraman, especially when the cameras have to be moved rapidly. Lastly, it is hardly possible to mount such cameras on motor vehicles or aircraft and at the same time aim them in a wobble-free and stable manner at a selected object.
The invention sets for itself the task of improving the apparatus of the kind described above such that it will pick up and display scenes in greater detail and/or follow moving subjects within the scene, without moving as a whole, and especially without having to be swung or tilted.